In a hydraulic fracturing process applied for an unconventional oil and gas, a large amount of water resources are consumed, and a large number of harmful additives contained in the fracturing fluid are prone to cause eco-environmental pollution. Consequently, a supercritical CO2 fracturing becomes one type of waterless fracturing technology which currently has been a developing focus.
Due to the complexity of the CO2 fracturing process, some of basic theory and method for the hydraulic fracturing are not fully applicable to a research on the supercritical CO2 fracturing. The existing researches on a supercritical CO2 mostly focus on the qualitative analysis of a fracture network structure formed after performing a CO2 fracturing. However, it is impossible to observe and characterize the fracturing process.
In the conventional art, a quantitatively analysis on the distribution and evolution law of a stress field in the process of fracture expansion is conducted by a numerical simulation method. However, the computational precision of the numerical simulation method is prone to be affected by external conditions. Consequently, the accuracy and reliability of a numerical simulation result cannot be ensured.